Extraction of gold.



E STATES 1 .mims WESTHEAD WORSEY, or sr. HELENS, AND EDWIN HOAL,

' or LIVERPOOL, ENGLAND.

Ex mAc-nom or; elem.

are. 846,768.

Specification of Letters Patent.

Patented March 12, 1907. A

To all whom it may concern: I

Be it known that we, JAMEs WESTHEA'D WORSEY and EDWIN HOAL, subjects of the King of England, and residents of St. Helens, in the county of Lancaster, England, and Liverpool, in the county of Lancaster, England, respectively, have invented certain new and I useful Improvements in or Connected with which the following is a specification.

This invention has reference to the extraction and separation of gold primarily from refractory gold ores-namely, from certain the Extraction of Goldfrom Gold Ores, of

oxidized deposits of decomposed granite and other like ores admixed with refractory m1neralssuch, for instance, as arsenic and antimonic acids, magnetite, &c.which are so combined or mixed with the gold as to make its extraction impossible, at least commercially, by known methods of treatment; but while the invention is more particularly directed to the treatment of such complex or refractory ores its application to the treatment of other. gold ores of a less refractory or complex nature and auriferous substances, in connection with which it can be usefully and advantageously employed; is embraced hereunder. 7

Accoiding to this invention the ore having first been reduced and screened and freed as much as possible from aluminium silicates in any known way, is treated with or subjected to the action of nascent bromid of chlorin produced in the body'and resenc'e of the traction low in ore by'mixing with the pow ered or crushed ore a salt of chlorate of soda and bromid of soda or a chlorate and bromid of other equivalent alkali or a chl'orid and bromid of an alkaline earth, the quantity needful for the effectual extraction of the gold varying with the richness of the'ore in that metal which must be determined by actual assay. The mixture is quietl stirred or mixed during the operation. here is added to this composition of admixed ore and chemicals some acid, as'hydrochloric, sulfuric, or other suitable acid, according to the chemical salts selected and used for the formation of this bromid of chlorin only in such suitable quantities and of dilute strengths as will not cause a too rapid reaction of the chemicals.

Otherwise the 'most valuable part of these-' lective reagent will be wasted and the exgold. The material may also be gently stirred at this period. Under this conditionthe reaction. will begin directly, and as it proceeds the temperature ofv the substance or material or mass should be regulated-that is, raised from time to time till it rises to about 150 Fahrenheit.

. When the mass or material, has been under ucts. At this stage the complex minerals are completely broken up and the gold dissolved. The whole is now allowed to settle, and the clear solution is decanted away, While the residue is well washed with hot water to extract from it all soluble gold, and this solution, together with the decanted solution, are mixed in a vat prepared for them and are treated with a sufficient a solution of an alkali or .an alka whereby any acid present is neutralized, care being taken that the neutralization is properlyeffected. A weak solution of alead salt is uantity of now added to the gold solution (the quantity of lead salt added depending u on the gold contained in the solution) and t ewhole vigorously stirred, with the effect that the gold contained in the solution is taken up by the lead salts. Sulfid of hydrogen (H 8) or other suitable known equivalent acid, either as as or in solution, is added to the Whole unti it turns'quite black,.and it should be again Well stirred or agitated by blowin through it a quantity of atmospheric air for some min: lites-say about ten to twenty minutes. In this condition the precipitated gold and lead sulfid will settle out completely, and the can be collected, dried, and calcined carefu ly in a mufiie-furnace and afterward melted with the addition of some lead in any suitable form in a smelting-furnace and the metallic lead, product refined in the bone-ash test in the well-known manner for the recovery of fine gold.

To recover any residual gold contained in the orepreviously separated from thegold solution, it is treated and washed in a vat with a weak solution of double or single ferroprussiate of ammonium and commercial soda carbonate after the manner of ordinary leaching. The eflect of this is that all the residuary gold in theore is dissolved out of it, and this is effected quicklynamely, within twenty-four hours. .The gold is disine earth,

Iio

solved out in the secure by Letters first stage as bromo chlorid, and afterward when heated it resolves itself into auric chlorid Au C1 In this treat ment the ferro-prussiate of ammonium acts as an expeditor or saver of time, and by it the residual ores of this and other gold-extraction processes can be economically treated and gold extracted and within a greatlyreduced time. The solution resulting from this leaching operation can be treated like the previous solution (after neutralization) with the lead-salt solution drogen (H 5) for the separation oi the auriferous lead sulfid, which may be smelted and refined in the same manner and by the same treatment as above described. r

' In the case of the application of the invention to the extracting of gold from rich concentrates it may be desirable and necessary to adopt more prolonged and careful operations and treatment.

-Having now particularly described our invention, what we claim as new, and desire to Patent, is-- 1. The process of extracting gold from gold ores, .by treating such gold ores to the action of nascent bromid of chlorin' produced b 'the admixture of a salt of chlorate of an alllaline substance, and bromid of an alkaline substance, and a suitable acid in the presence of the ore; substantially as and for the purposes set forth.

alkaline substance, l

seems 2. The process gold ores, by treating such gold ores to the action of nascent bromid of chlorin produced by the admixture of a salt of chlorate f an alkaline substance, and bromid of an alkaline substance, and. a suitable acid in the presence of the ore, and subjecting same to a gentle heat; and subsequently raising the temperature of the mixture; substantially as and for the purposes as herein set forth. 7

3 The process of extracting gold from gold ores, by treating such gold ores to the action of nascent bromid oi chlorin produced by the admixture of a sa and bromid of an alkaline substance subjecting same to heat; then separating. the gold solution from the undissolyed portion; then treating the gold solution with a weak solution of a lead salt added to it, and agitating same; and then subse quently treating it with acid, added to it, and subsequently agitating same, preferably by forcing air through it; set forth. In witness whereof we have hereunto set our hands in presence of two witnesses.

l JAMES WESTHEAD 'WORSEY.

EDWIN HOAL.

W'itn esses i ARTHUR MCDONALL HANNAY; l Roesa Benson.

oi extracting gold from lt of chlorate ofan substantially 

